[U-Boot] [PATCH v5 20/25] da850: Add README.da850

[Prabhakar Lad]

On Tuesday 28 August 2012 04:48 AM, Tom Rini wrote:
> This file documents when to build for da850evm and when to build for
> da850_am18xxevm.  It also documents how to write the u-boot.ais file to
> persistent storage (such as SPI), in some cases as well as how to write
> a recovery image.
> 
> Signed-off-by: Tom Rini <trini at ti.com>

Acked-by: Prabhakar Lad <prabhakar.lad at ti.com>

Regards,
--Prabhakar

> ---
> Changes in v2:
> - Add README.da850_am18xxevm
> 
> Changes in v3:
> - Fix thinko, Nand -> SPI (spotted by Prabhakar Lad)
> - Rename to README.da850, add more direct recovery method (Christian Riesch)
> 
> Changes in v4:
> - Further re-word README.da850 based on feedback from Christian Riesch
> 
>  board/davinci/da8xxevm/README.da850 |   68 +++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>  create mode 100644 board/davinci/da8xxevm/README.da850
> 
> diff --git a/board/davinci/da8xxevm/README.da850 b/board/davinci/da8xxevm/README.da850
> new file mode 100644
> index 0000000..621a95d
> --- /dev/null
> +++ b/board/davinci/da8xxevm/README.da850
> @@ -0,0 +1,68 @@
> +Summary
> +=======
> +The README is for the boot procedure used for various DA850 (or compatible
> +parts such as the AM1808) based boards.
> +
> +In the context of U-Boot, the board is booted in three stages. The initial
> +bootloader which executes upon reset is the ROM Boot Loader (RBL) and sits
> +in the internal ROM. The RBL initializes the internal memory and then
> +depending on the exact board and pin configurations will initialize another
> +controller (such as SPI or NAND) to continue the boot process by loading
> +the secondary program loader (SPL).  The SPL will initialize the system
> +further (some clocks, SDRAM) and then load the full u-boot from a
> +predefined location in persistent storage to DDR and jumps to the u-boot
> +entry point.
> +
> +AIS is an image format defined by TI for the images that are to be loaded
> +to memory by the RBL. The image is divided into a series of sections and
> +the image's entry point is specified. Each section comes with meta data
> +like the target address the section is to be copied to and the size of the
> +section, which is used by the RBL to load the image. At the end of the
> +image the RBL jumps to the image entry point.  The AIS format allows for
> +other things such as programming the clocks and SDRAM if the header is
> +programmed for it.  We do not take advantage of this and instead use SPL as
> +it allows for additional flexibility (run-time detect of board revision,
> +loading the next image from a different media, etc).
> +
> +
> +Compilation
> +===========
> +The exact build target you need will depend on the board you have.  For
> +Logic PD boards, or other boards which store the ethernet MAC address at
> +the end of SPI flash, run 'make da850evm'.  For boards which store the
> +ethernet MAC address in the i2c EEPROM located at 0x50, run
> +'make da850_am18xxevm'.  Once this build completes you will have a
> +u-boot.ais file that needs to be written to the correct persistent
> +storage.
> +
> +
> +Flashing the images to SPI
> +==========================
> +The AIS image can be written to SPI flash using the following commands.
> +Assuming that the network is configured and enabled and the u-boot.ais file
> +is tftp'able.
> +
> +U-Boot > sf probe 0
> +U-Boot > sf erase 0 +320000
> +U-Boot > tftp u-boot.ais
> +U-Boot > sf write c0700000 0 $filesize
> +
> +
> +Recovery
> +========
> +
> +In the case of a "bricked" board, you need to use the TI tools found
> +here[1] to write the u-boot.ais file.  An example of recovering to the SPI
> +flash of an AM1808 would be:
> +
> +$ mono sfh_OMAP-L138.exe -targetType AM1808 -p /dev/ttyUSB0 \
> +	-flash_noubl /path/to/u-boot.ais
> +
> +For other target types and flash locations:
> +
> +$ mono sfh_OMAP-L138.exe -h
> +
> +Links
> +=====
> +[1]
> + http://processors.wiki.ti.com/index.php/Serial_Boot_and_Flash_Loading_Utility_for_OMAP-L137
>